The Dengvaxia Issue and the Current Measles Outbreak

Q—Soon after the Dengvaxia controversy came to light, many public health experts were worried that the issue might affect the government’s immunization program. Has it?—remedios_alcase@yahoo.com

When the Dengvaxia controversy emerged in November 2017, many experts indeed expressed their fear that the issue would adversely affect our other immunization programs (DPT, measles, polio, etc.) as Filipino parents might increasingly believe that vaccines are harmful and refuse to vaccinate their children,

A year into the controversy, the immunization coverage of Filipino children is down from the previous years, the number of unimmunized children is accumulating and outbreaks are occurring. There are probably a number of reasons for these phenomena, but certainly the Dengvaxia scare contributed significantly to them.

The Dengvaxia issue

In 2016, the Department of Health (DOH) launched a massive dengue immunization program after Dengvaxia, the dengue vaccine developed by Sanofi Pasteur, was approved by the FDAfollowing clinical studies that showed it can protect individuals in the nine to 45 years age bracket against the four types of dengue viruses.

But in Nov. 2017, Sanofi Pasteur announced a huge change on its recommendations. It said that based on new analysis of up to six years of clinical data, Dengvaxia should be administered only to those who have been previously infected with the dengue virus and not to those who have not been infected, because for those in the latter group the risk for developing the severe form of dengue is higher following subsequent dengue infection.

The finger-pointing and disinformation that followed the announcement eroded the public’s confidence in the DOH and its immunization programs. The approval rating of the DOH immediately dropped to a low 60 percent. Thankfully, the DOH promptly recovered the people’s confidence and its approval rating was up to 78 percent by June 2018, but its immunization programs have not recovered yet.

Even after the DOH suspended its dengue immunization program and announced that the 800,000 children who received the vaccine will be closely monitored, the suspicious public could not be reassured. Worse, since then, deaths among children who have been immunized with Dengvaxia have been routinely attributed to the vaccine, never mind if post-mortem studies show other causes of death.

DOH immunization figures

The impact of the Dengvaxia issue can be clearly gleaned from the current immunization figures. The DOH annual vaccination target is 85 to 90 percent. This year, the projected year-end immunization coverage will only be 60 percent, which represents a more than 10 percent drop from the 70 percent registered last year.

Coverage rates for fully immunized children are also at a low 69 percent from the previous years’ results that ranged from 79 percent to 90 percent. For children to be considered fully immunized, they should receive the following vaccines: BCG, Oral Polio Vaccine (OPV), Diphtheria, Tetanus and Pertussis (DPT), Hepatitis B, and Haemophilusinfluenzae Type B, and Measles, Mumps and Rubella (MMR).

The current measles outbreak

Hardest hit by the low immunization coverage and growing number of unvaccinated children is the DOH measles elimination program. From Jan.1 to Nov. 10 last year, 17,298 cases of measles were recorded (with more than a hundred deaths), up from 3,706 recorded in the same period in 2017, an increase of 367 percent.

Measles outbreaks were declared by the DOH in 2018 in major areas, including Negros Oriental, a barangay in Taguig, Zamboanga City, Davao Region, and Davao City. When the health department launched its supplemental immunization program for measles called “Ligtas Tigdas” and went door-to-door in April 2018, only 36 percent or about four in 10 children in the National Capital Region received the vaccine. Evidently, mothers were hiding their children from the DOH personnel.

It is no surprise that among the immunizable diseases, measles is the first to manifest an outbreak. It is a highly contagious airborne viral disease that requires high immunization coverage—90-95 percent of people must be vaccinated in order to protect the entire population, or achieve what is called herd immunity.

If our immunization coverage continues to decline, outbreaks of other diseases will surely occur.

With hope, the Dengvaxia dispute will die down soon, although it probably will not. Vaccines are the main reason the mortality rate among infant and children in our country has gone down dramatically in the last few decades. It is a pity if we lose all we have gained because of one issue that has been blown out of proportion.